I'd try another monitor first (that's free if you know somebody with a monitor you can use for an hour or so), then another graphic card. If none of the two help, post again.
Need some help here, I built my own PC about a year ago and all was good at the beginning, it cost me about £1,200 and the hardware far surpasses the recommended hardware for any of the games I play.
Radeon R9 280x Msi Graphics card
16Gb of RAM
However a problem that is beginning to get worse and worse are these really odd pixelated squares that seem to crop up on a more and more frequent occasion. They seem to also react to me typing or moving the mouse as they flicker and it seems the patch of screen that one square covers, appears onto the other square. If anyone can give any advice whatsoever, if its maybe a hardware issue, or if it could be a fault in me building the computer. Sadly whenever I Print Screen, the cubes dont appear on the pasted image.